The Most MYSTERIOUS Object in the Universe

The Most MYSTERIOUS Object in the Universe

Hey, it’s Diana, and you’re
watching “Physics Girl.” I am very excited to
be back making videos, because I just got back from
a trip to New York City. I got to go to the Creator
Summit, the YouTube Creator Summit, and hang out with a
bunch of your favorite creators and my favorite creators
and schmooze and pretend like I belonged there. It was awesome, but that’s
not what this video is about. While I was there,
the last night, I stayed with my
friend Daniella, who’s an astrophysicist. And I cornered her
and made her tell me everything about her research. She told me this little
nugget about a conference that revolutionized the
field of astronomy. She may not have
used those words. But anyways, back
in 1995, astronomers held a conference
called “Cool Stars 9”– great name– in
Florence, Italy, where a huge announcement was made. The first gas giant
exoplanet, that is, the first planet
like Jupiter outside of our solar system,
had been discovered. That was crazy exciting news,
to think of planets outside of the eight that
we’re so familiar with. But unfortunately, it
probably overshadowed another announcement about
a much more mysterious type of object, the moon. Just kidding. No, astronomers had found the
first incontrovertible brown dwarf. Those two things
happened at the same time, so that was a crazy conference. DIANA: Yeah, that
like the conference to end all conferences. Yeah, seriously. I don’t know why we do
conferences anymore. So brown dwarfs, are
they stars like red dwarfs? No, they are really
confusing objects. Brown dwarfs are celestial
bodies that are in-between stars like the sun and
giant planets like Jupiter. So it’s way harder
to characterize them. Which makes them more fun. They’re like the liger
of celestial objects, like the BMW X6 is halfway
between a sedan and an SUV, as everyone knows. Did I get off topic? They’re intermediate in
terms of their properties, of how their atmospheres look,
most importantly, in terms of their mass. But we can generalize and
say that all brown dwarfs are about the size of Jupiter. However, they have about
8% of the mass of the sun. So they’re way, way denser. Despite being so much
more dense than planets, brown dwarfs are
still not dense enough to have the key trait
that defines a star. They can’t fuse
hydrogen in their core. And that’s important. In fact, brown dwarfs
were originally theorized as just that– as these objects that couldn’t
fuse hydrogen in their core. They were originally
called black dwarfs, but even back then they
were referred to as stars. The difficulty
is in understanding exactly where the difference
between a star and a brown dwarf. You’re gonna
discover that it’s really hard to draw the
line between a planet and a brown dwarf and
a star, which is weird, because that’s,
like, the number one thing that humans like to do– categorize things. How can you not know
whether something is a planet or a star? Although this confusion is the
whole reason for the debacle where Pluto got demoted. Anyways, the one
definite characteristic is that thing about
fusing hydrogen. Stars can fuse hydrogen
throughout their lives. And that fusion creates helium
and also releases light. The photons travel outwards
while the upper layers of the star are trying to push
inwards, and those two forces, you can imagine as
literally like two arrows going against each other. They stabilize the star. Brown dwarfs, of
the other hand, we think that they’re born
in a similar way as stars, but they don’t do enough
nuclear reactions in their core. They don’t do it at
a fast enough rate to actually hold them
together, you know, to actually prevent gravity
from compressing them. So because brown dwarfs
don’t do a lot of fusion and they don’t do
any hydrogen fusion, they don’t shine like stars. They’re faint. Plus, they’re small and cold. So we couldn’t find them. So back in the ’60s, there
was an important technology that we needed to
develop in order to be able to find brown dwarfs. I’m gonna pause this
story real quick and show you a photo that I took
when I was visiting my friend William Osmond. The device that I used to get
this photo of William Osmond is pretty spectacular. It takes photos of you
glowing, like, actually. William is emitting light,
not reflecting, not like light shining on you, reflecting. He’s glowing, but it’s
invisible to our eyes. It’s so far beyond the
red part of the spectrum that it’s infrared. And so we took that photo
with a little infrared camera. If you could see
infrared light, you would be able to see
William in the pitch dark. Awkward. Now, brown dwarfs are
pretty much the same. They’re mostly admitting
infrared light. So we needed to develop
infrared cameras, strong ones, specifically
infrared telescopes, in order to be
able to find them. It took almost like 35
years until they were finally discovered, because in the ’60s
we didn’t have any infrared telescopes. Therefore, it was
hard to spot one. But once we did have
a few candidates, it was still hard to tell
whether they were actually brown dwarfs until 1995. In ’95, it was announced that
a brown dwarf showing methane in their atmosphere
was discovered, and that was definitely
a brown dwarf. Since 1995, some of the
other original candidates have been confirmed, and so
have many more new candidates, but we still sometimes observe
objects and scratch our heads and say, “is it a brown dwarf? We’re not sure. How do we even
define brown dwarfs? We’re still working on that. There’s so many
open questions. It’s really interesting. So I think,
personally, the thing that I find most exciting
is that we don’t actually know how they form. We have all these
mechanism scenarios, like, that we think
how they could form, but we don’t really know. And for me, the most
interesting thing is trying to find
observational signatures as to what are brown
dwarf formation pathways and what are planet
formation pathways. Daniella and I
talked for, like, an hour about brown
dwarfs, because they are so fascinating. We didn’t get to talk much
about it, but one of Daniella’s deepest parts of
research– by the way, she has studied brown
dwarfs for like 10 years. This woman is an expert. I just spit a lot. And what she studies most– I was talking about that– is brown dwarf binaries, which
is where a brown dwarf is orbiting something else. Might be another brown dwarf. Cool stuff. Thank you so much to Daniella
for spending so much time with me answering my questions. One of coolest parts of my
job is that I– the scientists do all the work,
and then I just get to ask them as many questions
as I want and learn from them. I love it. I wanna make one
last announcement. As you know, I’m part of the
PBS Digital Studios network, and there’s another channel
on PBS Digital Studios called “above the noise.” What they are all
about is that they try to talk about controversial
and trending topics, like trolling, and get
the facts about them. So in that trolling
video, I was actually in there reading some
of your comments. So thank you guys for
providing the material. Anyways, that’s all I’ve
got for brown dwarfs. Thank you so much for
watching this video. Give it a thumbs up if
you want more space stuff. Subscribe if you wanna
learn more physics, like random stuff, with me. Thank you for watching,
and happy physicsing.

Only registered users can comment.

  1. is brown dwarf are really brown ? i don't think they are dwarf ….. but i can conclude that physic girl is a phenomena that makes me even more attracted to physics

  2. It really is no mystery to why the American public are so dumbed down and ignorant of anything scientific. With this kind of anti-science claptrap being bandied around as real science, the uneducated and gullible public are hopelessly disinformed about everything scientific.

  3. Maybe our own Jupiter ,Saturn, Uranus and Neptune are also brown dwarfts …ignoring infrared what kind of radiation do these objects generate to be declare as a stars?

  4. But i thought the critical mass explains it all? Brown Dwarfs did not reached the critical mass thus it could not perform fusion( or limited fusion) ? Humm…

  5. Can't a brown dwarf be a star which cannot be seen in visible light range because of gravitational red shift

  6. It might surprise you to learn that hydrogen-fusing-into-helium makes up less than half of all nuclear reactions in our Sun and that it's also responsible for less than half of the energy that the Sun eventually outputs.
    Lots of simplified explanations for how things work in physics.

  7. Diana, you are fun, you bring science to light, and are a most wonderful role model for young women. Well done!

  8. i really like this space stuff and tiny atoms stuff! cern must have done something new and cool to talk about? i loveyou explaining things that no one else does well, like quarks quantum science… i love einstein’s quote that if you can’t explain it to an 8 year old, then you don’t fully understand it… he would LOVE you.

  9. Is there a Brown Dwarf in the Oort Cloud? Ask you pal. If so, it ought to be dubbed YUGGOTH. It actually fulfills his description and location. Cheers.

  10. I don't know if u r aware of recent developments on the star. It now seems that stars r electric. And even more important, outside of our solar system the environment is regulated by electricity and not gravity( which cannot b explained by anyone)

  11. i have been thinking Jupiter could be a failed star because most solar systems out there have 2 stars/suns! what is your thoughts on this?

  12. I don´t think fusion goes on inside the sun, it is all happening on the surface… Why? Because all elements are found in the solar wind. If heavier elements sinks towards the core then none of it would be detected in space, but it does.

    Just admit it, science has gone bust on this!

  13. Bible says atheists. Scientists worship Satan its reason why we are 1000 years behind in all sciences cos churches banned it for a millennia.

  14. It seems that chemistry is the science behind Brown Dwarfs
    Reactions not fusion.
    It's gathering dust and other compound molecules from space perhaps a possible maybe.

  15. If I can still remember, Jupiter has a potential to become a star, it's just it lacks mass. So if Jupiter has enough mass, maybe it will turn into a brown dwarf first, then a star. Just a theory, though.

  16. There is an issue with fusion. Stars are hot and dense enough to support H1-H1 fusion. However, the presence of deuterium in ALL cosmic hydrogen, and the MUCH LOWER temperature required for D-D fusion, means that there is a size of object in which D-D fusion occurs without H1-H1 fusion. Since the ratio of deuterium to protium is .000156, such fusion would be VERY SLOW, but non-zero. Thus, brown dwarfs (and perhaps even Jupiter) produce energy from D-D fusion which accounts for their modest energy output that permits them to be detected.


  18. I've never been as annoyed by a presenter as I am by this presenter. Can someone tell me how to block content from a specific presenter?

  19. Try this what is space! Have a think or you can try agent carter antimatter and the dimension of space it lives on have you Seen the test 😨 and it's housed on a fabric but it's like behind you, be careful??? And matter is not on this side you need the hole to transfer (NOW what is space!.)

  20. Black holes and Quasars are way more mysterious though, but thank you so much for the enlightening video.

  21. Our Beloved once 9th PLANET? — YEAH GURL! I hold down McTyson Nuggets and you WAIL on his presumptive ares with a REEL HARD Kuiper Belt – LETS DO THIS!

  22. I just came across an interesting story relating to the moon. It's about how statistics really can be deceiving. Look at the moon compared to all the stars in the background. Compared to all those stars, the moon is as close insignificant as you can get. Yet, if you ask people, what impacts your lives more, the moon, or all the stars in the universe? People will say "the moon", that least significant fleck of cosmic crud, affects them more. So the least significant has the most prominence.

  23. Daniella says, at one point, that there's not enough fusion reactions in the core (of a brown dwarf) to hold it out against its gravity – does that mean that there is, literally, some fusion going on, but not enough?

  24. if sun fuses hydrogen how does sun get neutron; electron proton neutron; since neutron star is what is left when star goes nova; meaning neutron did not spontaneously come to exist; but it existed before went supernova; so where did neutron come from if sun fuses hydrogen; not byproduct?

  25. Cutest physics girl in the universe! Where did you find those rotating models looks like the moon & Jupiter ?

Leave a Reply

Your email address will not be published. Required fields are marked *